1. Field of the Invention
The present invention relates to a microsystem, e.g., micromechanical sensor structure, and to a method for the production of such a microsystem.
2. Description of the Related Art
Micromechanical sensor structures are known from the related art. Micromechanical rotation rate sensors for determining rates of rotation about one or more axes are used, for example, in the automotive sector and in entertainment electronics for navigation, image stabilization and detection of movement. Such rotation rate sensors have a movable micromechanical element enclosed in a cavity. To obtain low damping and thus a high mechanical Q factor, the micromechanical element is typically enclosed at a very low gas pressure, for example at from 1 to 5 mbar. Micromechanical acceleration sensors serve to determine accelerations in one or more directions in space and are used, for example, for electronic stabilization programs, for airbag release and for attitude detection. Such acceleration sensors also have a movable micromechanical element enclosed in a cavity. To obtain a critical damping and thus a rapid settling of the movable element, the micromechanical element is typically enclosed in a cavity with a relatively high gas pressure, for example of around 800 mbar. It is also known for a plurality of rotation rate sensors and acceleration sensors to be combined in an inertial navigation system which makes it possible to track position and orientation by time integration of the individual signals.
The enclosure of the micromechanical elements in the cavities is done by wafer-level encapsulation, for example by seal glass bonding or eutectic bonding. In that procedure, the pressure used during bonding is enclosed in the interior of the cavity. If a plurality of chips is implemented on one chip, all of the encasing cavities have the same internal pressure. When seal glass bonding is employed, the bond pressure is increased in addition by solvent evaporation from the seal glass.